By:Doug Miller
But the good news is that a tsunami will almost certainly never hit Long Island.
According to Professor William Holt, an expert on tectonophysics in the geology department at SUNY-Stony Brook, Long Island - and most of the northern Atlantic Ocean - is located on a tectonic plate that doesn't move much, so the plate collisions that lead to most major earthquakes won't happen here. They are not completely unheard of, though.
"In 1929, what's known as the Grand Banks earthquake led to a tsunami that hit coastal Canada near Nova Scotia," said Holt. "Where we are located is a passive continental margin, not an active one, so any earthquake on our margin would be within the plate's interior, which is very rare."
Tsunamis such as the one that hit South Asia Dec. 26 are generally caused by a submarine earthquake that raises the sea floor, causing a massive displacement of water. They most often occur in the Pacific Ocean, where submarine volcanic and tectonic activity is frequent, and they are very unpredictable. Holt said that an earthquake off the coast of Chile in the early 1900s created a tsunami that led to fatalities in Eureka, Calif., and caused shoreline damage in Alaska.
Because tsunamis are so infrequent in the Atlantic, there really isn't enough data on them to create a mathematical model to predict them. Two major earthquakes have been recorded in the eastern U.S. in the nation's history, the last in 1887 in Charleston, S.C. "We just don't have a long history of events," Holt said.
If a tsunami were to occur, he explained, it would most likely originate from a submarine earthquake in the Caribbean, where there is a little more plate movement. It would take a quake of at least magnitude 8.5 to sufficiently raise the sea floor to send a tsunami our way. There is nothing in science to say it can't happen, Holt said, but no reason to believe it ever will.
City officials in Long Beach, which would obviously take the brunt of a tsunami, said the city has evacuation plans in place for hurricanes, which are much more frequent and easily predictable, but not tsunamis.
A hurricane gives several days' notice, while a tsunami arrives within an hour or two of an earthquake. With an estimated evacuation time of 18 to 24 hours, residents of Long Beach's barrier island would probably be best off going to a house of worship, said an administration official who asked not to be named.
In preparing for a potential coastal emergency, the Village of Atlantic Beach installed a telephone emergency alert system in 2003, which can send a voice-mail message to every resident with a listed telephone number within three hours, which would be enough time for an evacuation before a hurricane, but not a tsunami. Atlantic Beach Mayor Stephen Mahler, second vice president of the Nassau County Village Officials Association, said he got the idea in 2002 during a meeting of the association. "To be able to inform all residents in advance of a storm is huge," said Mahler, whose village is the third in the county, along with Bayville and Manorhaven, to implement the system, and the first on the South Shore.
Despite having the emergency phone system in place for Atlantic Beach's roughly 2,000 residents, Mahler said he is still concerned about congestion on the village's evacuation route, Route 878 (the Nassau Expressway), as a result of recent construction projects along the highway. "I think that we are overlooking the problems with 878 ...," he said. "Where do you go other than 878 [in an emergency]?"
The current emergency-evacuation route for Atlantic Beach and residents in the Five Towns and Far Rockaway, as well as for the western portion of Long Beach, runs from Route 878 to the end of Peninsula Boulevard and onto Hempstead Turnpike to Hofstra University, and then into the Nassau Coliseum parking lot in Uniondale.
In an effort to change the route, local officials pressed Congress to approve an expanded $300 million Route 878 project, but it was not included in the 2004 federal highway bill passed by Congress. If the project were included in the bill, the highway, which currently stretches from the Atlantic Beach Bridge to Rockaway Turnpike, would have been elevated just past the Costco Wholesale Club, heading east along Rockaway Turnpike toward the Van Wyck Expressway and the Belt Parkway. An original proposal for the expansion of Route 878 was made in 1976, but the plan stalled.
Mahler also emphasized the importance of the task force that was created by Nassau County Executive Tom Suozzi so that Queens and Nassau County could be on the same page when it comes to future construction projects that could impact Route 878. A recent proposal to build a 150,000-square-foot shopping center in Queens, just over the Nassau border on Brookville Boulevard, near the evacuation route, was scrapped, but Mahler fears that another project might be proposed for the site that would add more traffic congestion.
"It is vital for the different agencies to work together, and Tom Suozzi has done more to connect the different forms of government than ever before," said Mahler.
For residents farther east, the Town of Hempstead also has evacuation plans in place and a readily available pamphlet offering tips for evacuation, such as bringing cash, prescription medicine, infant supplies, canned fruit, bottled water and pet food. Evacuation orders will be broadcast over local television and radio, and shelters will be made available.
But, again, these emergency plans are for hurricanes and floods, not tsunamis.
Andrew Cohen contributed to this story. Comments about it? DMiller@liherald.com or (516) 569-4000 ext. 213.
